1. Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland
2. Department of Histology and Embryology, Poznan University of Medical Sciences, 60-812 Poznan, Poland
3. Fertility, Infertility and Perinatology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
4. Division of Anatomy, Department of Human Morphology and Embryology, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
5. Physiology Graduate Program, North Carolina State University, Raleigh, NC 27695, USA
6. Prestage Department of Poultry Science, North Carolina State University, Raleigh, NC 27695, USA
7. Department of Veterinary Surgery, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland
8. Division of Anatomy and Histology, University of Zielona Góra, 65-417 Zielona Góra, Poland
9. Division of Histology and Embryology, Department of Human Morphology and Embryology Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
10. Division of Ultrastructural Research, Faculty of Medicine, Wroclaw Medical University, 50-368 Wroclaw, Poland
11. Center of Assisted Reproduction, Department of Obstetrics and Gynecology, University Hospital and Masaryk University, 602 00 Brno, Czech Republic
12. Department of Diagnostics and Clinical Sciences, Institute of Veterinary Medicine, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland